Discontinued in 2012, SolRay is a solar water heater device that heats water up to 83ºC, making it drinkable, safe to cook and wash by eliminating voltaic cells from the water. The product was developed by Technology for Tomorrow (t4t)’s workforce based in Kampala (Uganda) and distributed across Uganda until 2012.
The product cost includes installation labor but excluding transport, plumbing materials, and cold water reservoir
SDG 7: Affordable and Clean Energy
SDG 6: Clean Water and Sanitation
Market Suggested Retail Price
Target Users (Target Impact Group)
Distributors / Implementing Organizations
Technology for Tomorrow
Direct competitors include Solvatten Solar Safe Water System.
The Solray solar water heater device is individually manufactured by t4t in their workforce based in Kampala, Uganda.
Intellectural Property Type
User Provision Model
Users can obtain this product directly from the manufacturer.
Distributions to Date Status
57 devices have been distributed, from which 30 are in schools in Wakiso and Luweero districts and 27 in across households in Kampala, Uganda. Interview with representative
System dimensions (m)
Description of heater
Description of auxiliary heating sources
Water output temperature (deg C)
Storage tank capacity (L)
Design specifications include a water tank (12 depth x 250 width x 400 length mm) made from galvanized or mild steel plate with a glass sheet cover, and both the tank and glass are enclosed in a wooden box. Above the wooden box is a water reservoir or a connection to a water supply. The hot water that comes from the box can reach up to 80 ºC.Interview with representative The water tank can be used alone or connected in series to multiple tanks.
The solar water heater is installed by t4t, technical support is unknown. However, for further support users must contact the manufacturer.
Available from the manufacturer.Interview with representative
5 - 7 years. Over 7 years when galvanized steel is used.Interview with representative
Manufacturer Specified Performance Parameters
Vetted Performance Status
The manufacturer found that the product needed to improve the circulation of the water through the hot reservoir and that it should be constructed with materials that don't easily rust, such as galvanized steel metal sheets.Interview with representative The temperature of the water was an average of 65ºC with a high of about 80ºC. The product didn't rust for about 2-3 years.Interview with representative
There are no potential hazards reported to the use of this product. To pasteurize drinking water, the water must be heated to 55ºC. This requirement is exceeded with this device as it heats water up to 83ºC.
Complementary Technical Systems
Academic Research and References
Compliance with regulations
The production of this product has been suspended since 2012.Interview with representative t4t commercializes sanitary pads made from papyrus and paper waste (called Makapads) and interlocking stabilized soil blocks (ISSBS), stronger and more durable than the traditional fired brick. Some case examples can be seen on the organization's Facebook page.